On the origin and the spreading of the shallow Mediterranean water core in the Iberian basin

The origin and the spreading of the shallow Mediterranean water core (Ms) in the Iberian basin is discussed with a quasi-synoptic hydrographic data set enhanced by chlorofluoromethane (CFM) measurements. Its characteristic density level is found to be σ_t = 27.4. Characterized by high temperature and CFM values, Ms enters the Iberian basin in the region of Cape St Vincent between depths of 500–750 dbar. A heat anomaly of >11.8 × 10⁹ J m⁻² is chosen as the boundary between the presence of Ms and the background field. The core is found in a tongue-like shape as well as in separate isolated eddies of both cyclonic and anticyclonic circulation. Using the optimum multiparameter analysis (Tomczak and Large, 1989, Journal of Geophysical Research, 94, 16141–16149), the North Atlantic Central Water (NACW), which mixes with the Mediterranean outflow to form Ms, turned out to be in the mean 1°C warmer and 0.11 saltier than in regions with minor Mediterranean influence. This points to the Gulf of Cadiz as the origin of Ms, where the Mediterranean oufflows is in contact with NACW of the appropriate characteristics.     

Determination of the miscibility gap on the solid solution series paragonite-margarite by means of the infrared spectroscopy

In order to study the miscibility gap of the solid solution series margarite-paragonite oxide mixtures corresponding to intermediate compositions were crystallized at H₂O-pressures between 1 and 6 kb at 400 to 600 °C. Run products were examined by x-ray method and IR-spectroscopy; the latter proved to be the tool which allowed to distinguish between the two phases, the calcic and the sodic mica. A solvus exists in the region between 20 and 50 mole% margarite. Its width is temperature-dependent with a critical temperature above 600 °C.     

The influence of long-term storage on the salinity of bottled seawater samples

Summary An investigation is described which examines the influence of long-term storage on the salinity of bottled seawater samples in common soft glass bottles. Two experiments were carried out over independent time periods, the first one covering 7 months and the second one 16 months. The results show that long-term storage increases mean salinity and variance. During the first 6 months a rate of change of about 0.0012 in 30 days is observed. After that time the rate of change decreases to about 0.0004 per 30 days. The observed curve is interpreted as desorption of glass components into the seawater sample. Evaporation and the influence of efficient biological activities can be excluded confidently. For the salinity sample bottles used in the physical laboratories in Kiel the results make long-term stored salinity samples inappropriate for accurate in-situ calibration of modern CTD devices. The details of the chemical reactions were not investigated.